1. Field of the Invention
The present invention relates to a non-impact printer, and more particularly to a printer improved in printing quality to provide a natural printing image for a curve, a slash or the like.
2. Description of the Prior Art
Hitherto, in a non-impact printer such as an electrophotographic printer, an electrically charged photoconductor drum is illuminated with a light source to form an electrostatic latent image on a surface thereof, a developing is performed upon adhesion of a toner to the electrostatic latent image, to form a toner image, and then the thus obtained toner image is transferred to a recording material to be fixed thereon.
FIG. 2 is a block diagram of a printer control circuit for use in a conventional non-impact printer. In the figure, a printing control unit 1 transmits, at the time point that a sheet arrives at a printing ready point, a timing signal 12, including a line and a raster timing signal, to a host or another controller, and receives video data 11 which has been edited on each page in a host or another controller. The received video data 11 in the printing control unit 1 is transmitted to an LED (Light Emitting Diode) head 19 in the form of a real printing data signal 18. Upon receipt of a line of video data 11, the control unit 1 transmits a latch signal 17 to the LED head 19 so as to hold the real printing data signal 18 therein. Before receiving the subsequent data from a host or another controller, the thus held real printing data signal 18 is visualized in print when the print head 19 receives a printing drive signal 13. The real printing data signal 18 is transmitted to the LED head 19 in synchronism with a clock signal 18a.
Transmission and receipt operation of the video data 11 is performed in the unit of print lines. FIG. 3 is an operational time chart of the conventional non-impact printer as mentioned above.
However, according to the conventional non-impact printer as mentioned above, the printing is performed in accordance with image data or video data 11 transmitted from the host controller as it is, or depending on resolution of the LED head 19 which is determined by an arrangement of the LED devices at regular intervals in a raster direction. Thus, there will be retained a serrated edge-like image on a slash portion of the printed image due to the resolution.